> Those three links I saw already. They don't plug directly into your computer's USB > port. The ones you listed plug into a PCB's USB port or they plug into/replace > buttons.
Not sure what you mean. I've just bought a SpinTrak and it's plugged directly into PC's USB port. Windows detects it, loads the driver, job done.
There is also an Opti-pac version of the SpinTrak - maybe that's what you're getting confused with?